U.S. Pat. No. 3,814,261 issued Jun. 4, 1974 to Filter Specialists, Inc. (inventor: Howard MORGAN) discloses a filter assembly including a housing having a fluid inlet and a water outlet. A perforated basket lined with a filter sheet is fitted and supported within the housing in spaced relationship from the U-shape housing. A fluid is fed into the housing, and macroparticulate fluid contaminants are screened through the filter basket, wherein purified water engages in the U-gap between the basket and the housing wall, before escape through a bottom outlet port.
An important problem with this filter system is that the interval between successive maintenance interventions thereof is short. This interval is short, because the macroparticulate contaminant screened from the fluid deposit on the filter lining, thus clogging the screening bores of the filter lining. Once a layer of contaminant deposit has built up, the filter becomes inoperative with respect to its filtering properties.